I work for a company that uses outsourced contract developers paid hourly but physically located in our office. At the end of every month we get an excel sheet from their outsourcing companies with the appointed hours and the bill.
Many of these contractors 'cheat' when logging their hours. They will come in at 10:15am but bill from 10:00am, or they will log hours that they spent on personal business. Altogether, they are billing around 10% more hours than they are actually working.
If I bring up the problems with logging time there is a good chance I would have to look for replacements. While they may not be billing their time properly, they are getting the work done to an acceptable level. Finding replacements could be time-consuming and may be quite difficult.
Is it unprofessional to turn a blind eye to the billing discrepancies as long as I am satisfied with the quality of work?